[SPARK-14238][ML][MLLIB][PYSPARK] Add binary toggle Param to PySpark HashingTF in ML & MLlib

## What changes were proposed in this pull request?

This fix tries to add binary toggle Param to PySpark HashingTF in ML & MLlib. If this toggle is set, then all non-zero counts will be set to 1.

Note: This fix (SPARK-14238) is extended from SPARK-13963 where Scala implementation was done.

## How was this patch tested?

This fix adds two tests to cover the code changes. One for HashingTF in PySpark's ML and one for HashingTF in PySpark's MLLib.

Author: Yong Tang <yong.tang.github@outlook.com>

Closes #12079 from yongtang/SPARK-14238.

1 files changed, 22 insertions, 2 deletions

diff --git a/python/pyspark/ml/feature.py b/python/pyspark/ml/feature.py
index 0b0c573eea..809a513316 100644
--- a/python/pyspark/ml/feature.py
+++ b/python/pyspark/ml/feature.py
@@ -536,14 +536,19 @@ class HashingTF(JavaTransformer, HasInputCol, HasOutputCol, HasNumFeatures, Java
     .. versionadded:: 1.3.0
     """
 
+    binary = Param(Params._dummy(), "binary", "If True, all non zero counts are set to 1. " +
+                   "This is useful for discrete probabilistic models that model binary events " +
+                   "rather than integer counts. Default False.",
+                   typeConverter=TypeConverters.toBoolean)
+
     @keyword_only
-    def __init__(self, numFeatures=1 << 18, inputCol=None, outputCol=None):
+    def __init__(self, numFeatures=1 << 18, binary=False, inputCol=None, outputCol=None):
         """
         __init__(self, numFeatures=1 << 18, inputCol=None, outputCol=None)
         """
         super(HashingTF, self).__init__()
         self._java_obj = self._new_java_obj("org.apache.spark.ml.feature.HashingTF", self.uid)
-        self._setDefault(numFeatures=1 << 18)
+        self._setDefault(numFeatures=1 << 18, binary=False)
         kwargs = self.__init__._input_kwargs
         self.setParams(**kwargs)
 
@@ -557,6 +562,21 @@ class HashingTF(JavaTransformer, HasInputCol, HasOutputCol, HasNumFeatures, Java
         kwargs = self.setParams._input_kwargs
         return self._set(**kwargs)
 
+    @since("2.0.0")
+    def setBinary(self, value):
+        """
+        Sets the value of :py:attr:`binary`.
+        """
+        self._paramMap[self.binary] = value
+        return self
+
+    @since("2.0.0")
+    def getBinary(self):
+        """
+        Gets the value of binary or its default value.
+        """
+        return self.getOrDefault(self.binary)
+
 
 @inherit_doc
 class IDF(JavaEstimator, HasInputCol, HasOutputCol, JavaMLReadable, JavaMLWritable):